From owner-freebsd-arch Sun Oct 13 19: 0:28 2002 Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 4E53E37B401 for ; Sun, 13 Oct 2002 19:00:27 -0700 (PDT) Received: from softweyr.com (softweyr.com [65.88.244.127]) by mx1.FreeBSD.org (Postfix) with ESMTP id 888EC43E6E for ; Sun, 13 Oct 2002 19:00:26 -0700 (PDT) (envelope-from wes@softweyr.com) Received: from nextgig-9.access.nethere.net ([66.63.140.201] helo=softweyr.com) by softweyr.com with esmtp (Exim 3.35 #1) id 180uWd-0006ZN-00; Sun, 13 Oct 2002 20:00:07 -0600 Message-ID: <3DAA27F9.DBDA4EFE@softweyr.com> Date: Sun, 13 Oct 2002 19:12:10 -0700 From: Wes Peters Organization: Softweyr LLC X-Mailer: Mozilla 4.78 [en] (X11; U; Linux 2.4.2 i386) X-Accept-Language: en MIME-Version: 1.0 To: Christoph Hellwig Cc: Matthew Dillon , "Vladimir B. Grebenschikov" , Nate Lawson , arch@FreeBSD.ORG Subject: Re: Database indexes and ram (was Re: using mem above 4Gb was:swapon some regular file) References: <1034105993.913.1.camel@vbook.express.ru> <200210082015.g98KFFrq084625@apollo.backplane.com> <1034109053.913.7.camel@vbook.express.ru> <200210082051.g98KpjU1084793@apollo.backplane.com> <3DA4C271.37AACAA3@softweyr.com> <20021012135245.A16453@infradead.org> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Christoph Hellwig wrote: > > On Wed, Oct 09, 2002 at 04:57:37PM -0700, Wes Peters wrote: > > Linux solved this problem by refusing to do it. The candidates for DMA > > transfers include skbufs and buffers from the disk buffer pool, both of > > which are allocated from the lowest 4GB of physical ram when using PAE > > mode. > > Umm, Linux _does_ DMA into any memory if the NIC/HBA/whatever supports > it. And the driver has been modified. There are 3 or 4 drivers that have been, not a daunting majority by any stretch. -- "Where am I, and what am I doing in this handbasket?" Wes Peters Softweyr LLC wes@softweyr.com http://softweyr.com/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message